125: Genetic Diversity of Epstein-Barr Virus Latent Gene EBNA-1 Among Transplant Patients and Patients with Infectious Mononucleosis.
Bibliographic record
Abstract
Introduction: The distribution of Epstein Barr Virus (EBV)-associated pathologies varies worldwide. The EBNA-1 gene encodes a fundamental protein as it helps maintain the EBV episome and is expressed in all EBV-associated malignancies. It is unclear whether variation within EBNA-1 accounts for these different pathologies, or whether variation in the EBNA-1 sequence is simply due to varying geographical distribution. To compare DNA sequences between patients with different EBV associated pathologies, to see if these can be explained by different mutations. We sequenced the EBNA-1 gene from samples taken from transplant patients, which included asymptomatic transplant patients and patients with post-transplant lymphoproliferative disorder (PTLD), as well as patients with infectious mononucleosis (IM). Sequencing was done by Sanger methodology and the sequences were aligned with reference strains and compared with publically available databases. There were 20 samples; transplant = 11, IM = 9. Male to female ratio 1:1.2, age range 1–17 years. Of the transplant patients, four had PTLD. Phylogenetic trees showed there was great genetic diversity between strains when compared to publicly available sequences and no particular disease-related clustering. Within the carboxy terminal of EBNA-1 we found eighteen sites associated with amino acid substitutions; (residues 410, 429, 439, 471, 476, 487, 492, 499, 500, 502, 524, 525, 563, 574, 585, 588, 594, 595). Looking at the amino acid at position 487, transplant strains were more likely the P-Thr subtype, and less likely the P-Ala subtype, compared to IM strains; (71% of non-PTLD transplant strains were of the P-Thr subtype, compared to 75% of PTLD strains and 67% of IM strains, while 14% of non-PTLD strains were P-Ala, compared to 25% of PTLD strains and 33% of IM strains). Interestingly, 14% of non-PTLD transplant strains were of the V-Leu subtype. The percentage of amino acid substitutions was higher in the transplant patients, (52% in non-PTLD samples, 45% in PTLD samples, compared with 40% in IM samples). Conclusion: In conclusion, we generated 20 new EBNA-1 sequences from strains isolated in Toronto and showed that there is genetic diversity in EBNA-1 sequences within one city. Our initial findings suggest that the type and frequency of amino acid substitutions may vary between transplant patients compared with patients with infectious mononucleosis. Further research will define the significance of these observations, including the extent to which these findings relate to the severity of infectious mononucleosis or the genesis of EBV-related PTLD.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".